Clinical value of microbiological analysis of peri-pancreatic fluid collection and its impact on antibiotic management: A prospective multi-center study

Aims: Secondary infection of peri-pancreatic fluid collection (PPFC) that often accompanies pancreatic disorders is potentially life-threatening as it may lead to intra-abdominal abscess or sepsis. Microbiological analysis of aspirates from PPFC during endoscopic ultrasound (EUS) diagnosis/therapy to optimize the antibiotic treatment is rarely performed.

Aim of this study was to evaluate the role of routine aspirate from PPFC collection for microbiological analysis during EUS in the antibiotic management and to compare aspirates from PPFC with the corresponding concomitant blood culture.

Methods: In this prospective multi-center study, patients with PPFC needing EUS intervention were included. PPFC was aspirated through puncture set or biopsy needle. Concomitant blood cultures were drawn.

Results: 28 out of 51 patients (55%) had positive aspirate culture, whereas only two patients showed concomitant positive blood culture. 53 organisms could be identified in the positive aspirate cultures mostly gram positive bacteria (58%), gram negative bacteria (19%) and Candida spp. (19%) among others. In 86% of patients, pre-interventional antibiotics were administrated and adjustment of the antibiotic therapy according to the aspirate culture had to be performed in 79% of them. Positive culture results were associated with fever (p=0.026), acute pancreatitis (p=0.002), leukocytosis (p=0.001), elevated CRP (p=0.001) and longer hospital stay pre-intervention (p=0.001). Acute pancreatitis, leukocytosis and elevated CRP were independent risk factors for a positive aspirate culture.

Conclusion: Peri-pancreatic fluid collection is infected in a considerable proportion of patients, even in absence of fever, although most of them received pre-interventional antibiotics. Presenting with acute pancreatitis, leukocytosis or elevated CRP are independent risk factors for positive bacterial growth. Aspirate cultures is much more reliable than blood culture. A sample collected during EUS for microbiological analysis is a simple, potentially valuable, diagnostic tool in patients with peri-pancreatic fluid collection. Each center should recognize its own patterns of infection to ensure ideal targeted antibiotic therapy.